Flexible storage bag

ABSTRACT

The flexible storage bag includes overlaying first and second sidewalls defining an internal volume that can be accessed from an open top edge. To evacuate air from the internal volume after the open top edge has been closed, the bag includes a one-way valve element attached to the first sidewall and communicating with the internal volume. To prevent the one-way valve element from becoming clogged by the opposing second sidewall, the bag also includes a clearance member that maintains at least a partial clearance between the first and second sidewalls proximate the valve element. The clearance member can take many forms such as a textured portion on the second sidewall that includes evacuation passages which provide air in the internal volume access to the valve element, a permeable element covering the valve element, and a rigid or compressible structure that spaces the second sidewall from the valve element.

This application is a continuation of and claims priority under 35 USC §120 to application Ser. No. 10/880,784, filed Jun. 29, 2004, which isincorporated by reference herein.”

FIELD OF THE INVENTION

This invention pertains generally to storage containers and moreparticularly to flexible storage bags designed to be sealed andevacuated. The invention finds particular applicability in the field offood storage.

BACKGROUND OF THE INVENTION

Flexible plastic bags are widely used for a variety of purposes such asstoring food items, either temporarily as in the case of packagingsnacks or long term as in the case of freezer storage. Plastic bags ofthis style typically include flexible sidewalls made from, for example,polyethylene, that define an opening and an internal volume accessiblethrough the opening. To seal the bag, interlocking closure strips may beprovided about the rim of the opening.

One common problem which occurs with such bags is that, after theopening has been sealed, latent air may remain trapped in the internalvolume. In addition to undesirably increasing the overall size of thesealed bag, the trapped air can cause spoilation of food items stored inthe internal volume. Therefore, to remedy this problem, it is known toprovide a one-way valve element attached to a flexible sidewall andcommunicating with the internal volume. The one-way valve element allowsfor the evacuation of the trapped air from the internal volume whilealso preventing the ingress of air from the surrounding environment intothe internal volume. The one-way valve element may be activated invarious ways such as, for example, by applying compressive pressure tothe flexible sidewalls to force air from the internal volume or byengaging a nozzle of a vacuum source to the one-way valve element todraw air from the internal volume. An example of a one-way valve elementthat operates in conjunction with a vacuum source is provided in U.S.Pat. No. 6,581,641, issued to Skeens et al. and assigned to IllinoisTool Works Inc.

A problem that may arise with such bags that include one-way valveelements is that the flexible sidewall opposing the valve element andthe sidewall to which the valve element is attached can actually clogthe valve element preventing further evacuation. For example, it will beappreciated that placing the opposing sidewall against a solid surfaceand pressing the sidewall with the attached valve element toward thesurface evacuates the internal volume by collapsing the sidewallstogether. This also necessarily brings the opposing sidewall intocontact with the valve element which can result in clogging. Likewise,where a vacuum source is used to evacuate the flexible bag, the opposingsidewall may be drawn under vacuum pressure into the valve element. Arelated problem is that collapsing the opposing sidewalls themselvestogether may trap air in other portions of the internal volume. Theseand other problems are remedied by the invention described herein.

BRIEF SUMMARY OF THE INVENTION

The invention provides a clearance member for preventing the opposingsecond sidewall from clogging the one-way valve element whilemaintaining communication between the valve element and the internalvolume. The clearance member additionally hinders the collapsingtogether of the first and second sidewalls that results in trapping ofair in other portions of the internal volume.

In one aspect, the clearance member is provided as a textured portion onan inner surface of the sidewall that is opposite the valve element. Thetextured portion provides various evacuation passages that are recessedinto the opposing sidewall. Accordingly, even when the second sidewalland the valve element collapse adjacent to each other, the evacuationpassages communicate with an inlet to the valve element allowing forcontinued evacuation. In another aspect, the clearance member can be apermeable element attached to the inner surface of the first sidewall tocover the valve element. Accordingly, the second sidewall is preventedfrom collapsing adjacent to the valve element by the permeable element.The permeable element, however, is comprised of a material thatdemonstrates high air permeability so that air can continue to accessthe covered valve element.

In another aspect, the clearance member is provided as a rigid structureattached to the valve element or to the sidewalls proximate to the valveelement. The rigid structure spaces the opposing sidewalls apart fromeach other thereby allowing for continued evacuation. In yet anotheraspect, the clearance member may be a compressible structure attached tothe valve element or sidewalls. While the compressible structurecontinues to prevent the complete collapsing together of the sidewalls,it also compresses to minimize the space between the sidewalls and,accordingly, minimizes the air remaining in the internal volume.

Thus, an advantage of the invention is that it assists in preventing aone-way valve element from becoming clogged with an opposing flexiblesidewall. Another advantage is that it hinders the opposing sidewallsfrom collapsing together and thereby prevents the trapping of air withinthe internal volume. A related advantage is that the inventionfacilitates evacuation of air from the internal volume to, for example,preserve food items. These and other advantages and features of theinvention will become apparent from the detailed description and theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a flexible bag designed in accordancewith the teachings of the invention having an open top, a texturedportion, and an attached one-way valve element.

FIG. 2 is a front perspective view of an embodiment of a one-way valveelement for attachment to the flexible bag of FIG. 1.

FIG. 3 is a rear perspective view of the one-way valve element of FIG.2.

FIG. 4 is a cross-sectional view through the one-way valve element, astaken along line 4-4 of FIG. 2.

FIG. 5 is an exploded view of another embodiment of the one-way valveelement for attachment to the flexible bag.

FIG. 6 is an exploded view of another embodiment of the one-way valveelement for attachment to the flexible bag.

FIG. 7 is a cross-sectional view through the flexible bag and anembodiment of the one-way valve element engaging a nozzle of a vacuumsource with the sidewalls of the bag collapsed together and a path offlow through the valve element indicated, as taken along line 6-6 ofFIG. 1.

FIG. 8 is a detailed view of an embodiment of a textured portion on aninner surface of a sidewall of the flexible plastic bag, as taken aboutcircle 8-8 of FIG. 1.

FIG. 9 is a detailed view of another embodiment of a textured portionformed as a plurality of groove disposed into an inner surface of thesidewall, taken about circle 9-9 of FIG. 1.

FIG. 10 is a detailed view of another embodiment of a textured portionon an inner surface of a sidewall of the flexible plastic bag, as takenabout circle 10-10 of FIG. 1.

FIG. 11 is a perspective view of another embodiment of the flexible baghaving an open top, a textured portion along a side edge, and a one-wayvalve element.

FIG. 12 is a perspective view of another embodiment of the flexible baghaving an open top, a textured portion provided with a T-shape, and aone-way valve element.

FIG. 13 is a partial cross-sectional view through an embodiment of theflexible bag with the sidewalls of the bag collapsed together, as takenalong line 13-13 of FIG. 1.

FIG. 14 is a general schematic view illustrating a method for producinga flexible bag having a textured portion using continuous webs ofplastic.

FIG. 15 is a perspective view of another embodiment of a flexible baghaving an open top, a permeable element, and a one-way valve element.

FIG. 16 is a cross-sectional view through the flexible bag, permeableelement, and one-way valve element with the sidewalls of the bagcollapsed together, as taken about line 16-16 of FIG. 15.

FIG. 17 is a perspective view of a flexible bag having an open top, aone-way valve element, and a clearance member.

FIG. 18 is an exploded view of the flexible bag, the one-way valveelement, and clearance member of FIG. 17.

FIG. 19 is a cross-sectional view through the flexible bag, the one-wayvalve element engaged to a nozzle of a vacuum source, and the clearancemember with the sidewalls of the bag collapsed together and a path offlow through the valve element indicated, as taken along lines 19-19 ofFIG. 17.

FIG. 20 is a perspective view of a flexible bag having an open top, aone-way valve element, and another embodiment of the clearance member.

FIG. 21 is an exploded view of the flexible bag, the one-way valveelement, and the clearance member of FIG. 20.

FIG. 22 is a cross-sectional view through the flexible bag, one-wayvalve element, and the clearance member with the sidewalls of the bagcollapsed together and a path of flow through the valve elementindicated, as taken along line 22-22 of FIG. 20.

FIG. 23 is a perspective view of a flexible bag having an open top, aone-way valve element, and another embodiment of the clearance member.

FIG. 24 is a cross-sectional view of a flexible bag having a one-wayvalve element and a clearance member, the flexible bag being evacuatedby a vacuum nozzle with a path of flow indicated.

FIG. 25 is a perspective view of a flexible bag having an open top, aone-way valve element, and a compressible clearance member.

FIG. 26 is a perspective view of a flexible bag having an open top, aone-way valve element and another embodiment of a compressible clearancemember.

FIG. 27 is a perspective view of a flexible bag having a closable opentop with interlocking fastener strips and a slider, a one-way valveelement and an embodiment of the clearance member.

FIG. 28 is a cross-sectional view of the interlocking fasteners stripsengaging a movable slider for releasably closing the opened top, astaken along line 28-28 of FIG. 27.

FIG. 29 is a cross-sectional view of another embodiment of theinterlocking fastener strips engaging a movable slider for releasablyclosing the opened top, as taken along line 29-29 of FIG. 27.

FIG. 30 is a cross-sectional view of another embodiment of theinterlocking fastener strips engaging a movable slider for releasablyclosing the opened top, as taken along line 30-30 of FIG. 27.

FIG. 31 is a cross-sectional view of another embodiment of theinterlocking fastener strips engaging a movable slider for releasablyclosing the opened top, as taken along line 31-31 of FIG. 27.

DETAILED DESCRIPTION OF THE INVENTION

Now referring to the drawings, wherein like reference numbers refer tolike elements, there is illustrated in FIG. 1 an flexible bag 100designed in accordance with the teachings of the invention. In theillustrated embodiment, the flexible bag 100 includes a first sidewall102 and an opposing second sidewall 104 overlaying the first sidewall102 to define an internal volume 106. Accordingly, the first and secondsidewall 102, 104 each includes a respective first inner surface 108 andan opposing second inner surface 109. The first and second sidewalls102, 104 can be made from flexible webs of thermoplastic material suchas, for example, polyethylene. The webs may be monolayer or multilayerfilm typically used for food storage. Multilayer films may belaminations or coextrusions. Resins may include polyethylene includinghigh density (HDPE), low density (LDPE), linear low (LLDPE), nylon,ethylene vinyl alcohol (EVOH), polypropylene (PP), ethylene vinylacetate (EVA), polyester, ionomers or metallized films. Examples ofcoextruded multilayer film suitable for the current invention includelayered combinations such as HDPE/tie-layer/EVOH/tie-layer/LDPE ornylon/tie-layer/LDPE. For heat sealing, the sealant may be a blend ofmaterials such that when the bag is opened the peel does not result indestruction of the bag. One such sealant material would consist of ablend of LDPE and polybutene-1 commonly referred to as a peel-seal resinwhereby polybutene-1 is the minor phase. The first and second sidewalls102, 104 are sealed together along a first side edge 110, a parallelsecond side edge 112, and a closed bottom edge 114 that extendperpendicularly between the first and second side edges. To access theinternal volume 106, the portions of the first and second sidewalls 102,104 extending along an open top edge 116 remain unsealed. Due to thefour orthogonal edges, the flexible bag 100 has a generally rectangularshape. However, it will be appreciated that in other embodiments, thebag can have any suitable shape resulting from any number of sidewallsand edges.

To releasably close the opened top end 116 after insertion of an itemfor storage, there is attached to first and second sidewalls 102, 104and parallel to the open top edge respective first and second fasteningstrips 120, 122. The first and second fastening strips 120, 122 can beformed from extruded, flexible thermoplastic and extend between thefirst and second side edges 110, 112. As will be appreciated by those ofskill in the art, the first and second fastening strips 120, 122 canengage to form a seal which closes the normally open top edge 116. Ofcourse, in other embodiments or in combination with the interlockingstrips, other methods such as the use of pressure sensitive or cold sealadhesives such as those disclosed in U.S. Pat. No. 6,149,304, hereinincorporated by reference in its entirety, heat-sealing, or cling can beemployed to seal the open top edge.

To evacuate air trapped in the flexible bag 100 after sealing the opentop edge 116, the bag includes a one-way valve element 130 that isattached to the first sidewall 102 and communicates with the internalvolume 106. The one-way valve element 130 is capable of opening to allowentrapped air from the internal volume 106 to escape and closing toprevent to the ingress of environmental air into the internal volume.Communication with the internal volume 106 can be accomplished bydisposing an opening through the first sidewall 102 and then attachingthe valve element 130 over the opening.

Referring to FIGS. 2, 3, and 4, in an embodiment, the one-way valveelement 130 can include a rigid valve body 132 that cooperates with amovable disk 134 to open and close the valve element. The valve body 132includes a circular flange portion 136 extending between parallel firstand second flange faces 140, 142. Concentric to the flange portion andprojecting from the second flange face 142 is a circular boss portion138 which terminates in a planar boss face 144 that is parallel to thefirst and second flange faces. The circular boss portion 138 is smallerin diameter than the flange portion 136 so that the outermost annularrim of the second flange face 142 remains exposed. The valve body 132can be made from any suitable material such as a moldable thermoplasticmaterial like nylon, HDPE, high impact polystyrene (HIPS),polycarbonates (PC), and the like.

Disposed concentrically into the valve body 132 is a counter-bore 148.The counter-bore extends from the first flange face 140 part way towardsthe boss face 144. The counter-bore 148 defines a cylindrical bore wall150. Because it extends only part way toward the boss face 144, thecounter-bore 148 forms within the valve body 132 a preferably planarvalve seat 152. To establish fluid communication across the valve body,there is disposed through the valve seat 152 at least one aperture 154.In fact, in the illustrated embodiment, a plurality of apertures 154 arearranged concentrically and spaced inwardly from the cylindrical borewall 150.

To cooperatively accommodate the movable disk 134, the disk is insertedinto the counter-bore 148. Accordingly, the disk 134 is preferablysmaller in diameter than the counter-bore 148 and has a thickness asmeasured between a first disk face 156 and a second disk face 158 thatis substantially less than the length of the counter-bore 148 betweenthe first flange face 140 and the valve seat 152. To retain the disk 134within the counter-bore 148, there is formed proximate to the firstflange face 140 a plurality of radially inward extending fingers 160.The disk 134 can be made from any suitable material such, as forexample, a resilient elastomer.

Referring to FIG. 4, when the disk 134 within the counter-bore 148 ismoved adjacent to the fingers 160, the valve element 130 is in its openconfiguration allowing air to communicate between the first flange face140 and the boss face 144. However, when the disk 134 is adjacent thevalve seat 152 thereby covering the apertures 154, the valve element 130is in its closed configuration. To assist in sealing the disk 134 overthe apertures 154, a sealing liquid can be applied to the valve seat152. Furthermore, a foam or other resilient member may be placed in thecounter-bore 148 to provide a tight fit of the disk 134 and the valveseat 152 in the closed position.

Referring to FIG. 1, to establish the one-way aspect of the valveelement 130, the valve element is attached to the first sidewall 102with the apertures exposed to the internal volume 106 and the firstflange face exposed on the exterior of the flexible bag 100.Accordingly, referring to FIGS. 1 and 4, it will be appreciated thatevacuation of entrapped air will move the disk 134 adjacent the fingers160 thereby configuring the valve element 130 as opened while theingress of air from the environment will move the disk adjacent thevalve seat 152 thereby configuring the valve element as closed.

To attach the valve element 130 to the first sidewall, referring to FIG.3, an adhesive can be applied to the exposed annular rim portion of thesecond flange face 142. The valve element 130 can then be placedadjacent the exterior surface of the first sidewall with the bossportion 138 being received through the hole disposed into the sidewalland thereby pass into the internal volume. Of course, in otherembodiments, adhesive can be placed on other portions of the valveelement, such as the first flange face, prior to attachment to thesidewall.

In other embodiments, the one-way valve element can have a differentconstruction. For example, as illustrated in FIG. 5, the one-way valveelement 170 can include a flexible, circular base layer 172 thatcooperates with a correspondingly circular shaped, resilient top layer174 to open and close the valve element. The top and bottom layers canbe made from any suitable material such as, for example, a flexiblethermoplastic film. Disposed through the center of the base layer 172 isan aperture 176, thus providing the base layer with an annular shape.The top layer 174 is tautly stretched over and adhered to the base layer172 by two parallel strips of adhesive 178 that extend along either sideof the aperture 176, thereby covering the aperture with the top layerand forming a channel. The base layer 172 and top layer 174 are thenadhered by a ring of adhesive 182 to the flexible bag 100 so as to coverthe hole 180 disposed through the first sidewall 102.

As will be appreciated by those of skill in the art, when the sidewalls102, 104 of the bag 100 are forcibly compressed together, air from theinternal volume 106 will pass through the hole 180 and the aperture 176thereby partially displacing the top layer 174 from the base layer 172.The air can then pass along the channel formed between the adhesivestrips 178 and escape to the environment. When the force on thesidewalls 102, 104 is released, the resilient top layer 174 will returnto its stretched configuration covering and sealing the aperture 176.The valve element 170 may also contain a viscous material such as anoil, grease, or lubricant between the two layers in order to prevent airfrom reentering the bag. In an embodiment, base layer 172 may also be arigid sheet material.

Illustrated in FIG. 6 is another embodiment of the valve element 184that can be attached to the flexible plastic bag 100. The valve element184 is a rectangular piece of flexible thermoplastic film that includesa first end 186 and a second end 187. The valve element 184 is attachedto the first sidewall 102 so as to cover and seal a hole 188 disposedthrough the first sidewall 102. The valve element 184 can be attached tothe sidewall 102 by patches of adhesive 189 placed on either side of thehole 188 so as to correspond to the first and second ends 186, 187. Whenthe sidewalls 102, 104 of the flexible bag 100 are collapsed together,air from the internal volume 106 displaces the flexible valve element184 so at to unseal the hole 188. After evacuation of air from theinternal volume 106, the valve element 184 will again cover and seal thehole 188. As will be appreciated by those of skill in the art, otherembodiments of one-way valve elements can be used with the flexibleplastic bag such as, for example, an elastomer slit valve, duckbillvalve or check valve.

Referring to FIG. 1 and from the foregoing description, it will beappreciated that if the inner surface 109 of the flexible secondsidewall 104 is allowed to collapse adjacent to the first sidewall 102proximate to the location of the one-way valve element 130, the valveelement may become clogged preventing further evacuation of the bag 100.To prevent clogging of the valve element 130 by the sidewalls 102, 104,in accordance with the teachings of the invention, the bag 100 isprovided with a clearance member in the internal volume 106. Theclearance member maintains at least a partial clearance between thefirst and second sidewalls 102, 104 proximate the location of the valveelement 130 to allow air from the internal volume 106 to access thevalve element for exhausting.

Referring to FIGS. 1 and 7, in accordance with one aspect of theinvention, the clearance member is provided by texturing a portion 190of the inner surface 109 of the second sidewall 104 that corresponds tothe location of the one-way valve element 130 attached to the firstsidewall 102. The textured portion 190 includes a plurality ofalternating raised peaks 192 and recesses 194 that are formed into theinner surface 109. As illustrated in FIG. 7, when the valve element 130is engaged to the nozzle 196 of a vacuum source to evacuate the internalvolume 106 such that the first and second sidewalls 102, 104 collapseadjacent to each other, the raised peaks 192 contact the boss face 144of the valve element 130 thereby providing clearances that function asevacuation passages within the recesses 194. Accordingly, the recesses194 allow air, indicated by arrow 198, from within the internal volume106 to continually access the valve element 130 and thus the texturedportion 190 prevents clogging of the valve element.

The vacuum source connected to the nozzle 196 in FIG. 7 can be anysuitable vacuum source including, for example, hand-operated pumps,mechanical pumps, water aspirators, oral suction, and the like.Alternatively, the flexible bag can be evacuated by collapsing theflexible sidewalls together.

In the embodiment illustrated in FIG. 8, the peaks 192 can be formedalong the crests of a first plurality of raised ridges 200 that extendalong the inner surface. The first plurality of ridges 200 can bearranged parallel to and spaced-apart from each other. The recesses 202are therefore defined within the clearances between the ridges 192. Inthe illustrated embodiment, a second plurality of parallel ridges 206extends along the inner surface normal to and intersecting the firstplurality of ridges 200 to form a grid-like pattern. In an alternativeembodiment, the recesses can be formed within a grid-like pattern ofgrooves disposed into the inner surface, thus forming the raised peaksas a series of protuberances separated by the grooves. For example, inthe embodiment illustrated in FIG. 9, a first and a second plurality ofgrooves 212, 213 are disposed into the textured portion 109 and arearranged orthogonally to each other. The grooves 212, 213 define aplurality of raised portion 214 that are square in shape. It will beappreciated that air can communicate along the grooves 212, 213 betweenthe raised portions 214 even after the sidewalls have been collapsedtogether. In another embodiment illustrated in FIG. 10, the texturedportion 190 can include protuberances 208 having smaller, circularshapes that are randomly dispersed along the inner surface 109 that aresegregated from each other by arbitrarily-shaped recessed spaces 210therebetween. Of course, the textured portion can have any othersuitable shape, such as diamond-shaped ridges or grooves, horizontallyarranged ridges or grooves, vertically arranged ridges or grooves,patterned or random curved-shaped ridges or grooves, etc.

Referring to FIG. 1, the textured portion 190 can be provided oversubstantially the entire second inner surface 109 between the first andsecond side edges 110, 112 and between the closed bottom edge 114 andfastening strips 120, 122. Moreover, the first inner surface 108 of thefirst sidewall 102 can likewise be provided with a textured portion. Abenefit of providing the textured portion throughout the bag is that therecesses extend over the inner surface and are interconnected with oneanother. Accordingly, air at any location within the internal volume 106can access the valve element 130 along the interconnected recesses evenas the opposing first and second sidewalls 102, 104 collapse together,thereby preventing air in the internal volume from becoming trapped.

Of course, in other embodiments, the textured portion need not beprovided over substantially the entire inner surface. For example, inthe embodiment illustrated in FIG. 11, the textured portion is providedas a relatively narrow, vertical strip 220 along the first edge 110 ofthe second sidewall 104 arranged to correspond to the valve element 130.The remainder of the second inner surface is formed as a substantiallysmooth portion 222. An advantage of providing the textured portion as anarrow strip 220 adjacent the smooth portion 222 is that food itemsstored in the internal volume 106 are less likely to contact thetextured portion, and are therefore less likely to retain unsightlyimpressions upon removal from the bag 100. In another embodimentillustrated in FIG. 12, the textured portion is provided as a T-shape224 having a horizontal strip 226 and an intersecting vertical strip228. The horizontal strip 226 extends between the first and second sideedges 110, 112 while being spaced-apart from the bottom edge 114. Thevertical strip 228 extends between the bottom edge 114 and thehorizontal strip 226 while being spaced-apart from the first and secondside edges 110, 112. Accordingly, the T-shape textured portion 224 canextend substantially throughout the internal volume 106 between theopposing side edges 110, 112 and the top and bottom edges 114, 116 whilestill providing substantially smooth portions 230, 232.

In another embodiment illustrated in FIG. 13, to maximize exhaustion ofthe flexible bag wherein the textured portion is located on both thefirst and second sidewalls 102, 104, the peaks 234 and recesses 236 canbe arranged and sized to cooperate so as to minimize the remaininginternal volume as the sidewalls collapse together. For example, thepeaks 234 located on each sidewall are received in correspondingrecesses 236 formed on the opposing sidewall to interlock together.

To produce a flexible bag having a textured portion, webs of flexiblethermoplastic material can be manipulated through a high speedmanufacturing process such as that illustrated in FIG. 14. In themanufacturing process, a first web 240 of thermoplastic material iscontinuously unwound from a roll 242 and aligned in and advanced along amachine direction 244 through the processing machines. The first web ofmaterial 240 accordingly has a first surface 246 and a second surface248.

A second web 250 of thermoplastic material is provided wound onto asecond roll 252 located below the first roll. Embossed into the materialof the second web 250 are pluralities of peaks and recesses that formthe textured portion of the finished flexible bag. The second web 250 iscontinuously unwound from the second roll 252 and aligned with themachine direction 244 where it is attached to the second surface 248 ofthe advancing first web 240 by web attachment rollers 254. As will beappreciated, the attached first and second webs 240, 250 will form thesecond sidewall of the finished flexible bag.

To provide the first sidewall, a third web 260 of thermoplastic materialis provided wound onto roll 262. The third web 260 is continuouslyunwound and aligned with the first and second webs 240, 250 in themachine direction 244. After alignment, the third web 260 is attached tothe first and second webs 240, 250 at a second set of web attachmentrollers 264. In order to form the open top edge of the finished bag, thethird web 260 is only attached to the first and second webs 240, 250along a first edge 268 of the combined webs while the parallel secondedge 269 remains unattached.

To provide the fastening strips on the finished bag, the first andsecond fastening strips 270, 272 can be provided as elongatedthermoplastic extrusions wound onto first and second strip rolls 274,276. The first fastening strip 270 is unwound and aligned with the thirdweb 260 to which the first fastening strip is attached by stripattachment rollers 278. The second fastening strip 272 is unwound andaligned in the machine direction 244 with the first and second webs towhich the second fastening strip is continuously attached by striprollers 280. As illustrated in FIG. 14, the first and second fasteningstrips 270, 272 are aligned with the unattached second edge 269 of thecombined webs. Preferably, attachment of the fastening strips to thecontinuously advancing webs of thermoplastic material occurs between thefirst and second web attachment rollers 254, 264.

As the attached webs and strips are advanced in the machine direction244, the side edges of the finished bag may be produced by an edgingmachine 282. Specifically, the edging machine 282 forms a seal 284across the width of the attached webs and then cuts perforations 286along the seal. The perforated webs can then be folded by a foldingmachine 288 and wound into a roll 290 for distribution. Later,individual bags can be unwound and detached from the roll 290 along theperforated seals.

In another embodiment, instead of providing the textured portion in theform of a separate web of material, the textured portion can be formeddirectly onto the first web 240 of advancing material. For example, thesecond roll 252 and second web 250 of material can be eliminated and thefirst web attachment rollers 254 can be replaced with an embossingmachine that forms the peaks and recesses directly onto the first web240.

In another aspect of the invention, as illustrated in FIGS. 15 and 16,the clearance member can be provided as a permeable element 308 locatedin the internal volume 306 of the flexible bag 300. In addition to thepermeable element 308, the flexible bag 300 includes overlaying firstand second sidewalls 302 and 304 that are sealed together along firstand second side edges 310, 312 and a closed bottom edge 314. To accessthe internal volume 306, the edges of the first and second sidewalls302, 304 that are parallel to the closed bottom edge 314 remain unsealedto form an open top edge 316. To releasably close the open top edge 316after insertion of an item, first and second fastening strips 320, 322are provided. To evacuate air from the flexible bag after sealing thefastening strips, a one-way valve element 330 is attached to the firstsidewall 302 and communicates with the internal volume 306.

The permeable element 308 can be provided as a thickened planar sheetoutlined by a peripheral edge 309 that defines the shape of thepermeable element. The permeable element can be attached by, forexample, adhesive to an inner surface 324 of the first sidewall 302 suchthat the permeable element overlays and covers the one-way valve element330. In another embodiment, the permeable element 308 can be attached tothe second sidewall 304 opposite the valve element 330. The permeableelement 308 is characterized in that it comprises a material thatdemonstrates a high degree of air permeability.

As illustrated in FIG. 16, during evacuation of the flexible bag 300, asthe second sidewall 304 collapses toward the first sidewall 302, aninner surface 326 of the second sidewall 304 contacts the permeablematerial 308 and is therefore spaced-apart from the valve element 330.Air from the internal volume 306 of the bag 300, however, can stillaccess the exposed peripheral edge 309 of the permeable element andpermeate through to the valve element 330.

Examples of various permeable materials suitable for the permeableelement include any of various nonwoven materials such as, but notlimited to, melt blown, spun bond, hydroentangled, needle punched,batting, dry-laid or wet-laid. Preferably, the selected nonwovenmaterial demonstrates a hydrophobic property that permits air topermeate through but retains liquids. As will be appreciated, such ahydrophobic permeable material would prevent fluids from leaking throughthe one-way valve element or from drying out within the valve element. Apreferred material is polypropylene but the nonwoven material could alsobe made from polyester, nylon, or polyethylene. Other examples ofsuitable permeable materials include porous materials such as opencelled foams such as sponges, porous substrates, and sintered materials.

In another aspect of the invention, the clearance member can be providedas a rigid structure that functions to space the sidewalls apart fromeach other in the proximity of the valve element during evacuation. Therigid clearance member may include slots or notches disposed into itthat permit air from the internal volume to access the valve element.Because of the combined effect of the rigid clearance member in spacingthe sidewalls apart and providing access to the valve element, cloggingof the valve element is prevented. Preferably, the rigid clearancemember is engaged to the valve element itself but in some embodimentsthe rigid clearance member can be attached to the opposing sidewall.

An embodiment of the rigid clearance member in the form of a band 460engaged to a valve element 430 attached to a flexible bag 400 isillustrated in FIG. 17. The flexible bag 400 is formed from overlappingfirst and second flexible sidewalls 402, 404 that are joined alongparallel first and second side edges 410, 412 and a closed bottom edge414 to define an internal volume 406. To access the internal volume 406,the portions of the first and second sidewalls opposite the closedbottom edge 414 remain unsealed to form an open top edge 416. Toreleasably close the open top edge 416 after insertion of an item, firstand second fastening strips 420, 422 are provided.

Referring to FIG. 18, the band 460 can be shaped as an annular ringhaving a first face 462 and an opposing second face 464. Disposed intothe second face 464 of the annular band 460 along the perimeter are aplurality of notches 466 that extend toward the first face 462. Toengage the band 460 to the valve element 430, the valve element includesa circular flange portion 436 from which projects a smaller, circularboss portion 438. The boss portion 438 of the valve element 430 isinserted through an appropriately sized hole 470 formed into the firstsidewall 402 of the flexible bag. When the valve element 430 is thusattached, it will be appreciated that the boss portion 438 projects intothe internal volume 406 towards the second sidewall 404.

Preferably, the inner diameter of the band 460 is sized to slidably fitabout the circular, projecting boss portion 438. Accordingly, when theboss portion 438 and band 460 are fit together, the first sidewall 402is sandwiched between the valve element 430 and band. So that the secondface 464 of the band 460 projects into the internal volume, the lengthof the band between the first and second faces 462, 464 is greater thanthe length of the projecting portion 438 between the second flange face442 and the boss face 444. In various embodiments, the band and the bossportion can be secured by adhesive, friction fit, or can be an integralportion of the valve

As illustrated in FIG. 19, when a nozzle 496 of a vacuum source isengaged to the valve element 430 so as to evacuate the flexible bag 400such that the second sidewall 404 collapses toward the first sidewall402, the inner surface 409 of the second sidewall contacts the secondface 464 of the band 460 and is therefore spaced-apart from the valveelement 430. Air, indicated by arrow 486, from the internal volume 406of the bag 400 can still access the valve element 430 through thenotches 466 disposed through the band 460. Specifically, if the notches466 are sufficiently narrow and extend far enough toward the first face462 of the band, it will be appreciated that the second sidewall 404cannot be completely drawn into the notches. Hence, the valve element430 is prevented from clogging by the band 460. Preferably, the band andthe valve element are made of a moldable thermoplastic material.

The vacuum source connected to the nozzle 496 in FIG. 19 can be anysuitable vacuum source including, for example, hand-operated pumps,mechanical pumps, water aspirators, oral suction, and the like.Alternatively, the flexible bag can be evacuated by collapsing theflexible sidewalls together.

In FIG. 20, another embodiment of the rigid clearance member in the formof a cap 560 is illustrated engaged to a valve element 530 attached to aflexible bag 500. As described above, the flexible bag 500 also includesoverlapping first and second sidewalls joined along parallel first andsecond side edges 510, 512 and a perpendicular closed bottom edge 514 todefine an internal volume 506. To access the internal volume 506, theportions of the first and second sidewalls 502, 504 opposite the closedbottom edge 514 remain unsealed to form an open top edge 516. Toreleasably close the open top edge 516 after insertion of an item, firstand second fastening strips 520, 522 are provided.

Referring to FIG. 21, the cap 560 includes a circular cap top 562 fromthe periphery of which extends a perpendicular cap wall 564. Disposedthrough the intersection of the cap top and cap wall are a plurality ofperipheral apertures 566 while disposed through the center of the captop is a central aperture 568. To engage the cap 560 to the valveelement 530, the valve element includes a circular flange portion 536from which projects a smaller, circular boss portion 538. The bossportion 538 of the valve element 530 is inserted through anappropriately sized hole 570 formed into the first sidewall 502 of theflexible bag. When the valve element 530 is thus attached, it will beappreciated that the boss portion 538 projects into the internal volume506 towards the second sidewall 504. Preferably, the inner diameter ofthe peripheral cap wall 564 is sized to slidably fit about the circular,projecting boss portion 538. Accordingly, when the boss portion 538 andcap wall 564 are fit together, the first sidewall 502 is sandwichedbetween the valve element 530 and cap 560. In various embodiments, thecap and the boss portion can be secured together by adhesive, frictionfit, or be an integral portion of the valve.

As illustrated in FIG. 22, during evacuation of the flexible bag 500 asthe second sidewall 504 collapses toward the first sidewall 502, theinner surface 509 of the second sidewall contacts the cap top 562 of thecap 560 and is therefore spaced-apart from the valve element 530. Inthis situation, the central aperture 568 becomes covered by the secondsidewall 504. Air, indicated by arrow 578, from the internal volume 506of the bag 500 can still access the valve element 530 through theperipheral apertures 566 disposed through the cap 560. Hence, the valveelement 530 is prevented from clogging by the cap 560. An advantage ofthe cap 560 over the aforementioned band is that cap top 562 morecompletely prevents the second sidewall 504 from collapsing adjacent tothe valve element 530. Additionally, to improve the evacuation of theinternal volume 506, the central aperture 568 provides substantialadditional access to the valve element 530 than the peripheral apertures566 standing alone, at least prior to the central aperture becomingcovered by the second sidewall 504. Preferably, the cap 560 is made froma moldable thermoplastic material.

Illustrated in FIG. 23 is another embodiment of a rigid clearance memberin the form of an elongated sleeve 660 engaged to a valve element 630attached to a flexible bag 600. As described above, the flexible bag 600includes overlapping first and second sidewalls 602, 604 that are joinedalong parallel first and second side edges 610, 612 and a perpendicularclosed bottom edge 614 that define an internal volume 606. To access theinternal volume 606, the portions of the first and second sidewalls 602,604 opposite the closed bottom edge 614 remain unsealed to form an opentop edge 616. To releasably close the open top edge 616 after insertionof an item, first and second fastening strips 620, 622 are provided.

The elongated sleeve 660 is formed as a cylindrical structure thatextends between a first face 662 and a second face 664. Disposed throughthe sleeve 660 about the periphery are a plurality of slots 666. Thecylindrical sleeve 660 can be sized to slideably engage with thecircular valve element 630 in the above described manner with the secondface 664 projecting into the internal volume 606 towards the secondsidewall 604. Referring to FIG. 23, it will be appreciated that as thefirst and second sidewalls 602, 604 collapse towards each other, thesleeve 660 will function to space the sidewalls apart in the proximityof the valve element 630. The slots 666 disposed through the sleeve 660,however, will continue to allow air to access the one-way valve element630 from the internal volume 606. Hence, the valve element is preventedfrom clogging by the sleeve. Preferably, the sleeve is made from amoldable thermoplastic or a formed strip of metal.

Illustrated in FIG. 24 is a flexible bag 700 having attached to it aone-way valve element 730 of the type disclosed in U.S. Pat. No.6,581,641, herein incorporated by reference. The flexible bag 700 alsoincludes a first sidewall 702 to which the valve element 730 is attachedand an opposing second sidewall 704. The one-way valve element 730includes a resilient cap 732 that is mounted to a valve base 734. Theresilient cap 732 includes an outer wall 736 that surrounds a centralstem 738. The valve element 730 also includes a valve gate 734 thatnormally sits against a valve seat face 740 that is formed on the valvebase 734. To evacuate the flexible bag 700, a vacuum nozzle 780 thatcommunicates with a vacuum source can engage the valve element 730. Thenozzle 780 engages the valve element 730 by pressing the nozzle againstthe outer wall 736 of the cap 732. This forces the stem 738 downwardswhich displaces the valve gate from the valve seat surface 740. Air frominside the flexible plastic bag can then access the nozzle.

It will be appreciated that when the nozzle 780 is pressed against thevalve element 730, the second sidewall 704 can collapse against and clogthe valve element. To prevent this from occurring, an embodiment of theclearance member 760 is attached to the valve element 730. The clearancemember 760 is formed as a circular wall extending between a first end764 and a second end 766. The first end 764 is attached to the valvebase 734 such that the second end 766 is directed towards the secondsidewall 704. Disposed through the circular wall 762 are a plurality ofapertures 770 through which air, indicated by arrow 768, can pass.Accordingly, when the vacuum nozzle 780 is pressed against the cap 732,the clearance member 760 prevents the second sidewall 704 from enteringand clogging the valve element 730.

In another aspect of the present invention, the clearance element can beprovided as compressible structure comprised from a compressiblematerial. The compressible clearance member can be attached to eitherthe valve element or to an inner surface of a sidewall proximate thevalve element. Accordingly, the compressible clearance member willprevent the sidewalls from completely collapsing together proximate thevalve element. An advantage of utilizing the compressible clearancemember is that while the sidewalls remain spaced-apart, the compressibleclearance member compresses to minimize the air remaining in theinternal volume. Another advantage of utilizing a compressible clearancemember is that the compressible clearance member urges back against thesidewalls. Therefore, if the valve element were to become clogged by thesidewalls, the compressible structure could unclog the valve element byurging the first and second sidewalls apart.

Referring to FIG. 25, an embodiment of a flexible bag 800 having acompressible clearance member in the form of a spring 860 engaged to aone-way valve element 830 is illustrated. As described above, theflexible bag 800 includes overlapping first and second sidewalls 802,804 that are joined along parallel first and second side edges 810, 812and a perpendicular closed bottom edge 814 that define an internalvolume 806. To access the internal volume 806, the portions of the firstand second sidewalls 802, 804 opposite the closed bottom edge 814 remainunsealed to form an opened top edge 816. To releasably close the openedtop edge 816 after insertion of an item, first and second fasteningstrips 820, 822 are provided.

The spring 860 is formed as helical spring comprised of a plurality ofhoops 866 that extends between a first end 862 and a second end 864. Thefirst end 862 engages the valve element 830 by, for example, adhesiveattachment such that the second end 864 projects into the internalvolume 806 toward the second sidewall 804. In other embodiments, thespring can be secured to the valve element by a friction fit, asnap-lock engagement, or adhesive. During evacuation, as the first andsecond sidewalls 802, 804 collapse together, the second sidewall 804will contact the second end 864 of the spring 860 and begin to compressthe spring towards the first sidewall. Conversely, the spring 860 willurge the second sidewall 804 away from the valve element 830 preventingthe valve element from becoming clogged. Moreover, because of thesubstantial space between the alternating hoops 866 of the spring 860,air will continue to access to the valve element 830. Preferably, thespring is made from any suitable resilient material such as spring steelor a resilient thermoplastic. In another embodiment, a structurecomprising a tube with axially-spaced, collapsible, accordion pleats andholes disposed therethrough can be employed as the compressibleclearance member.

Illustrated in FIG. 26 is another embodiment of a flexible bag 900having a compressible clearance member in the form of compressible foamelements 960 attached to the flexible bag proximate to a one-way valveelement 930. As described above, the flexible bag 900 includesoverlapping first and second sidewalls 902, 904 that are joined alongparallel first and second side edges 910, 912 and a perpendicular closedbottom edge 914 that define an internal volume 906. To access theinternal volume 906, the portions of the first and second sidewalls 902,904 opposite the closed bottom edge 914 remain unsealed to form an opentop edge 916. To releasably close the open top edge 916 after insertionof an item, first and second fastening strips 920, 922 are provided.

The compressible foam elements 960 are shaped as rectangular blocks ofporous foam attached to the inner surface of the first sidewall 902 oneither side of valve element 930. However, in other embodiments, thefoam elements can be attached to the second sidewall in a manner toalign with the valve element. Additionally, in other embodiments, thefoam element can have other shapes, such as circular, square, annular,or polygon The foam elements 960 extend into the internal volume 906 andterminate at respective foam top surfaces 962 that are located closertoward the second sidewall 904 than the valve element 930. Duringevacuation, as the first and second sidewalls 902, 904 collapse towardseach other, the second sidewall will contact the foam top surfaces 962and begin to compress the foam blocks 960 towards the first sidewall902. Conversely, the foam blocks 960 will urge the second sidewall 904away from the valve element 930 preventing the valve element fromclogging. Because of the porous character of the foam blocks 960, airwill continue to have access to the valve element. Preferably, the foamblocks are formed from foamed rubber.

In another aspect of the invention, the flexible bag having a one-wayvalve element and clearance member can be provided with fastening stripsactivated by a slider. For example, referring to FIG. 27, there isillustrated a flexible bag 1000 having overlapping first and secondsidewalls that are joined along parallel first and second side edges1010, 1012, and a perpendicular closed bottom edge 1014 to define aninternal volume 1006. To access the internal volume 1006, the portionsof the first and second sidewalls 1002, 1004 that are opposite theclosed bottom edge 1014 remain unjoined to form an open top edge 516. Toreleasably close the open top edge 1016, the flexible bag 1000 includesa first fastening strip 1030 and a second fastening strip 1031 thatengage a movable slider 1032.

As shown in FIG. 28, the fastening strips may be U-channel fasteningstrips as described in U.S. Pat. No. 4,829,641, herein incorporated byreference in its entirety. U-channel fastening strips include a firstfastening strip 1030 with a first closure element 1036 and a secondfastening strip 1031 with a second closure element 1034. The firstclosure element 1036 engages the second closure element 1034. The firstfastening strip 1030 may include a flange 1063 disposed at the upper endof the first fastening strip 1030 and a rib 1067 disposed at the lowerend of the first fastening strip 1030. The first fastening strip 1030may include a flange portion 1069. Likewise, the second fastening strip1031 may include a flange 1053 disposed at the upper end of the secondfastening strip 1031 and a rib 1057 disposed at the lower end of thesecond fastening strip 1031. The second fastening strip 1031 may includea flange portion 1059. The sidewalls 1002, 1004 of the plastic bag 1000may be attached to the fastening strips 1030, 1031 by conventionalmanufacturing techniques.

The second closure element 1034 includes a base portion 1038 having apair of spaced-apart parallely disposed webs 1040, 1041, extending fromthe base portion 1038. The base and the webs form a U-channel closureelement. The webs 1040, include hook closure portions 1042, 1044extending from the webs 1040, 1041 respectively, and facing towards eachother. The hook closure portions 1042, 1044 include guide surfaces 1046,1047 which serve to guide the hook closure portions 1042, 1044 foroccluding with the hook closure portions 1052, 1054 of the first closureelement 1036.

The first closure element 1036 includes a base portion 1048 including apair of spaced-apart, parallely disposed webs 1050, 1051 extending fromthe base portion 1048. The base and the webs form a U-channel closureelement. The webs 1050, 1051 include hook closure portions 1052, 1054extending from the webs 1050, 1051 respectively and facing away fromeach other. The hook closure portions 1052, 1054 include guide surfaces1045, 1055, which generally serve to guide the hook closure portions1052, 1054 for occlusion with the hook closure portions 1042, 1044 ofthe second closure element 1034. The guide surfaces 1045, 1055 may alsohave a rounded crown surface.

The slider 1032 includes a top portion 1072. The top portion provides aseparator 1043 having a first end and a second end wherein the first endmay be wider than the second end. In addition, the separator 1043 may betriangular in shape. When the slider is moved in the occlusiondirection, the separator 1043 deoccludes the fastening strips 1030, 1031as shown in FIG. 11. Referring to FIG. 1, the closure elements 1034,1036 are deoccluded and specifically, the upper hook portions 1042, 1052and the lower hook portions 1044, 1054 are deoccluded.

The interlocking fastening strips may comprise “arrowhead-type” or “riband groove” fastening strips as shown in FIG. 29 and as described inU.S. Pat. No. 3,806,998 herein incorporated by reference in itsentirety. The rib element 1105 interlocks with the groove element 1107.The rib element 1105 is of generally arrow-shape in transverse crosssection including a head 1110 comprising interlock shoulder hookportions 1111 and 1112 generally convergently related to provide a camridge 1113 generally aligned with a stem flange 1114 by which the headis connected in spaced relation with respect to the supporting flangeportion 1108. (U.S. Pat. No. 3,806,998, Col. 2, lines 16-23). At theirsurfaces nearest the connecting stem flange 1114, the shoulder portions1111 and 1112 define reentrant angles therewith providing interlockhooks engageable with interlock hook flanges 1115 and 1117 respectivelyof the groove element 1107. (U.S. Pat. No. 3,806,998, Col. 2, lines23-28). Said hook flanges generally converge toward one another and arespread open to receive the head 1110 therebetween when said head ispressed into said groove element 1107 until the head is fully receivedin a groove 1118 of said groove element 1107 generally complementary tothe head and within which the head is interlocked by interengagement ofthe head shoulder hook portions 1111 and 1112 and the groove hookflanges 1115 and 1117. (U.S. Pat. No. 3,806,998, Col. 2, lines 28-36).Through this arrangement, as indicated, the head and groove elements1105 and 1107 are adapted to be interlockingly engaged by being pressedtogether and to be separated when forcably pulled apart, as by means ofa generally U-shaped slider 1119. (U.S. Pat. No. 3,806,998, Col. 2,lines 36-41).

The slider 1119 includes a flat back plate 1120 adapted to run alongfree edges 1121 on the upper ends of the sections of the flange portions1108 and 1109 as shown in the drawing. (U.S. Pat. No. 3,806,998, Col. 2,lines 41-46). Integrally formed with the back plate 1120 and extendingin the same direction (downwardly as shown) therefrom are respectivecoextensive sidewalls 1122 with an intermediate spreader finger 1123extending in the same direction as the sidewalls at one end of theslider. (U.S. Pat. No. 3,806,998, Col. 2, lines 46-51). The sidewalls1122 are in the form of panels which are laterally divergent from anarrower end of the slider. (U.S. Pat. No. 3,806,998, Col. 2, lines51-55). The slider walls 1122 are each provided with an inwardlyprojecting shoulder structure 1124 flange adapted to engage respectiveshoulder ribs 1125 and 1127 on respectively outer sides of the lowersection of the flange portions 1108 and 1109. (U.S. Pat. No. 3,806,998,Col. 2, line 66 to Col. 3, line 3).

Additionally, the interlocking fastening strips may comprise “profile”fastening strips, as shown in FIG. 30 and described in U.S. Pat. No.5,664,299 herein incorporated by reference in its entirety. As shown inFIG. 30, the first profile 1216 has at least an uppermost closureelement 1216 a and a bottommost closure element 1216 b. (U.S. Pat. No.5,664,299, Col. 3, lines 25-27). The closure elements 1216 a and 1216 bproject laterally from the inner surface of strip 1214. (U.S. Pat. No.5,664,299, Col. 3, lines 27-28). Likewise, the second profile 1217 hasat least an uppermost closure element 1217 a and a bottommost closureelement 1217 b. (U.S. Pat. No. 5,664,299, Col. 3, lines 28-30). Theclosure elements 1217 a and 1217 b project laterally from the innersurface of strip 1215. (U.S. Pat. No. 5,664,299, Col. 3, lines 30-32).When the bag is closed, the closure elements of profile 1216 interlockwith the corresponding closure elements of profile 1217. (U.S. Pat. No.5,664,299, Col. 3, lines 32-34). As shown in FIG. 13, closure elements1216 a, 1216 b, 1217 a and 1217 b have hooks on the ends of the closureelements, so that the profiles remain interlocked when the bag isclosed, thereby forming a seal. (U.S. Pat. No. 5,664,299, Col. 3, lines34-37).

The straddling slider 1210 comprises an inverted U-shaped member havinga top 1220 for moving along the top edges of the strips 1214 and 1215.(U.S. Pat. No. 5,664,299, Col. 4, lines 1-3). The slider 1210 hassidewalls 1221 and 1222 depending from the top 1220. (U.S. Pat. No.5,664,299, Col. 4, lines 3-4). A separating leg 1223 depends from thetop 1220 between the sidewalls 1221 and 1222 and is located between theuppermost closure elements 1216 a and 1217 a of profiles 1216 and 1217.(U.S. Pat. No. 5,664,299, Col. 4, lines 26-30). The fastening assemblyincludes ridges 1225 on the outer surfaces of the fastening strips 1214and 1215, and shoulders 1221 b and 1222 b on the sidewalls of theslider. (U.S. Pat. No. 5,664,299, Col. 4, lines 62-65). The shouldersact as means for maintaining the slider in straddling relation with thefastening strips by grasping the lower surfaces of the ridges 1225.(U.S. Pat. No. 5,664,299, Col. 5, lines 4-7).

Also, the interlocking fastening strips may be “rolling action”fastening strips as shown in FIG. 31 and described in U.S. Pat. No.5,007,143 herein incorporated by reference in its entirety. The strips1314 and 1315 include profiled tracks 1318 and 1319 extending along thelength thereof parallel to the rib and groove elements 1316 and 1317 andthe rib and groove elements 1316, 1317 have complimentarycross-sectional shapes such that they are closed by pressing the bottomof the elements together first and then rolling the elements to a closedposition toward the top thereof (U.S. Pat. No. 5,007,143, Col. 4, line62 to Col. 5, line 1). The rib element 1316 is hook shaped and projectsfrom the inner face of strip 1314. (U.S. Pat. No. 5,007,143, Col. 5,lines 1-3). The groove element 1317 includes a lower hook-shapedprojection 1317 a and a relatively straight projection 1317 b whichextend from the inner face of strip 1315. (U.S. Pat. No. 5,007,143, Col.5, lines 3-6). The profiled tracks 1318 and 1319 are inclined inwardlytoward each other from their respective strips 1314 and 1315. (U.S. Pat.No. 5,007,143, Col. 5, lines 6-8).

The straddling slider 1310 comprises an inverted U-shaped plastic memberhaving a back 1320 for moving along the top edges of the tracks 1318 and1319 with sidewalls 1321 and 1322 depending therefrom for cooperatingwith the tracks and extending from an opening end of the slider to aclosing end. (U.S. Pat. No. 5,007,143, Col. 5, lines 26-31). A separatorfinger 1323 depends from the back 1320 between the sidewalls 1321 and1322 and is inserted between the inclined tracks 1318 and 1319. (U.S.Pat. No. 5,007,143, Col. 5, lines 34-36). The slider 1310 has shoulders1321 a and 1322 a projecting inwardly from the depending sidewalls 1321and 1322 which are shaped throughout the length thereof for cooperationwith the depending separator finger 1323 in creating the rolling actionin opening and closing the reclosable interlocking rib and grooveprofile elements 1316 and 1317. (U.S. Pat. No. 5,007,143, Col. 5, lines43-49).

In other embodiments, the fastening strips noted above may also be usedwithout the slider.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

1. A plastic storage bag for storing food items comprising: a firstsidewall of flexible thermoplastic material; a second sidewall offlexible thermoplastic material overlaying and joined to the firstsidewall along a peripheral edge to provide an internal volume betweenopposing first and second inner surfaces of the respective first andsecond sidewalls, the internal volume accessible through an openingdisposed through the peripheral edge; first and second interlockingclosure strips attached respectively to the first and second innersurfaces for releasably closing the opening; and a one-way valve elementattached to the first sidewall proximate an intersection of theperipheral edge and the opening, the valve element communicating withthe internal volume, the valve element including a base layer having anaperture disposed therein and a top layer adhered to the base layer tocover the aperture, the valve element attached to the first sidewall tocover a hole disposed through the first sidewall.
 2. The bag of claim 1,wherein the base layer is annular and the top layer is circular.
 3. Thebag of claim 1, wherein the base layer and the top layer are comprisedof flexible thermoplastic film.
 4. The bag of claim 1, wherein the valveelement further includes a viscous material between the base and toplayers.